[Aging and so called "youth hormones". Potential influence of exercise training].

Plasma levels of dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor-I (IGF-I), and testosterone decline with ageing. These hormones share some biological activities which counteract the aging processes: increase in fat-free mass, decrease of adipose tissue and globally increased fitness and well being. It seems that lower levels of these hormones may reflect partially lower physical activity and fitness of older subjects. If further longitudinal studies confirm this, regular participation in exercise training would become a useful alternative to hormone replacement therapy.